Reliability is often a key requirement when it comes to using wireless networks in critical systems. For example, in industrial control systems, wireless sensors could transmit process variable data to access points throughout an industrial facility. The process variable data may be required for safe and effective control of an industrial process. The reliability of the wireless transmissions therefore typically needs to be high so that the necessary process variable data can be collected and used to control the industrial process.
In some conventional wireless sensor networks, an access point that successfully receives a data packet from a wireless sensor transmits an acknowledgement, and the wireless sensor need not retransmit the data packet. However, if the access point determines that the data packet has errors, the access point does not send the acknowledgement, and the wireless sensor retransmits the data packet. If a specified number of retransmissions fail, the wireless sensor can drop the data packet.